Java 如何在不执行另一个查询的情况下在我的图表中获得不同的计数？

我正在使用jaspersoft studio 6.2。我已经将条形图放在摘要栏中，如何将其设置为计算值表达式中某个字段的不同值？ e、 g

我有这个查询/数据集：

select 'xx' as UsageDate, 'a' as ProductName, 1 as CustomerKey
    union all select 'xx' as UsageDate, 'b' as ProductName, 1 as CustomerKey
    union all select 'xx' as UsageDate, 'a' as ProductName, 2 as CustomerKey
    union all select 'yy'as UsageDate, 'a' as ProductName, 1 as CustomerKey
    union all select 'yy' as UsageDate, 'b' as ProductName, 3 as CustomerKey

我想要达到的是

select usagedate, productname, count(distinct customerkey) as val from (
    select 'xx' as UsageDate, 'a' as ProductName, 1 as CustomerKey
    union all select 'xx' as UsageDate, 'b' as ProductName, 1 as CustomerKey
    union all select 'xx' as UsageDate, 'a' as ProductName, 2 as CustomerKey
    union all select 'yy'as UsageDate, 'a' as ProductName, 1 as CustomerKey
    union all select 'yy' as UsageDate, 'b' as ProductName, 3 as CustomerKey    
    ) as t
    group by usagedate, productname

usagedate

属于类别，

productname

属于系列。如何将图表中的值设置为

count（distinct customerkey）

？我知道我可以使用第二个查询作为数据集，并将val字段设置为图表中的值，但我还需要在报告中显示详细信息，因此只需一个查询/数据集即可

---

这可能吗

图表需要一个数据源，因此在子数据集中执行另一个查询无疑是最简单的方法。但是，如果您不想重新查询，另一种解决方案是使用报表scriptlet

创建一个类，该类扩展覆盖afterDetailEval从字段中获取值，存储值及其计数

然后，让您的scriplet返回图表的名称

编辑：如评论中所要求的简单示例

小纸条

public class CountScriptlet extends JRDefaultScriptlet {

    private static final String COUNT_FIELD = "fieldNameYouLikeToCount";

    //Map to hold our count and dataset
    private Map<String,CountResult> ds = new HashMap<String, CountResult>(); 

    @Override
    public void afterDetailEval() throws JRScriptletException
    {
        String key = (String)this.getFieldValue(COUNT_FIELD);
        CountResult cr = ds.get(key); //Check if we have it
        if (cr==null){
            cr = new CountResult(key); //No, then create it count = 0
            ds.put(key, cr);
        }
        cr.increment(); //Increment it (new 0-->1, old i-->i+1

    }   
    public JRBeanCollectionDataSource getDataSource(){
        return new JRBeanCollectionDataSource(ds.values()); //Return our class as datasource, if you need to sort'em use Collections
    }
}

public class CountResult {

    private String description;
    private int count;

    public CountResult(String description) {
        this.description = description;
    }
    public String getDescription() {
        return description;
    }
    public void setDescription(String description) {
        this.description = description;
    }
    public int getCount() {
        return count;
    }
    public void setCount(int count) {
        this.count = count;
    }

    public void increment(){
        count++;
    }
}

<subDataset name="countDatasource" uuid="f6b4337c-45f4-4fc6-909a-ffbbef3a1b2f">
    <field name="description" class="java.lang.String"/>
    <field name="count" class="java.lang.Integer"/>
</subDataset>

告诉jrxml使用scriplet（您需要指明完整的类名，包括包名）

在

jasperReport

标记集

scriptletClass=“CountScriptlet”

定义子数据集

public class CountScriptlet extends JRDefaultScriptlet {

    private static final String COUNT_FIELD = "fieldNameYouLikeToCount";

    //Map to hold our count and dataset
    private Map<String,CountResult> ds = new HashMap<String, CountResult>(); 

    @Override
    public void afterDetailEval() throws JRScriptletException
    {
        String key = (String)this.getFieldValue(COUNT_FIELD);
        CountResult cr = ds.get(key); //Check if we have it
        if (cr==null){
            cr = new CountResult(key); //No, then create it count = 0
            ds.put(key, cr);
        }
        cr.increment(); //Increment it (new 0-->1, old i-->i+1

    }   
    public JRBeanCollectionDataSource getDataSource(){
        return new JRBeanCollectionDataSource(ds.values()); //Return our class as datasource, if you need to sort'em use Collections
    }
}

public class CountResult {

    private String description;
    private int count;

    public CountResult(String description) {
        this.description = description;
    }
    public String getDescription() {
        return description;
    }
    public void setDescription(String description) {
        this.description = description;
    }
    public int getCount() {
        return count;
    }
    public void setCount(int count) {
        this.count = count;
    }

    public void increment(){
        count++;
    }
}

<subDataset name="countDatasource" uuid="f6b4337c-45f4-4fc6-909a-ffbbef3a1b2f">
    <field name="description" class="java.lang.String"/>
    <field name="count" class="java.lang.Integer"/>
</subDataset>

在您喜欢的地方使用数据源（图表、表格ecc.）

---

唯一的限制是报表需要填写详细栏位（完成计数），因此您可以在

摘要

栏位中使用它，或者在

reportElement

上使用

evaluationTime=“report”

您的图表需要一个数据源，因此毫无疑问，在子数据集中执行另一个查询是最简单的方法。但是，如果您不想重新查询，另一种解决方案是使用报表scriptlet

创建一个类，该类扩展覆盖afterDetailEval从字段中获取值，存储值及其计数

然后，让您的scriplet返回图表的名称

编辑：如评论中所要求的简单示例

小纸条

public class CountScriptlet extends JRDefaultScriptlet {

    private static final String COUNT_FIELD = "fieldNameYouLikeToCount";

    //Map to hold our count and dataset
    private Map<String,CountResult> ds = new HashMap<String, CountResult>(); 

    @Override
    public void afterDetailEval() throws JRScriptletException
    {
        String key = (String)this.getFieldValue(COUNT_FIELD);
        CountResult cr = ds.get(key); //Check if we have it
        if (cr==null){
            cr = new CountResult(key); //No, then create it count = 0
            ds.put(key, cr);
        }
        cr.increment(); //Increment it (new 0-->1, old i-->i+1

    }   
    public JRBeanCollectionDataSource getDataSource(){
        return new JRBeanCollectionDataSource(ds.values()); //Return our class as datasource, if you need to sort'em use Collections
    }
}

public class CountResult {

    private String description;
    private int count;

    public CountResult(String description) {
        this.description = description;
    }
    public String getDescription() {
        return description;
    }
    public void setDescription(String description) {
        this.description = description;
    }
    public int getCount() {
        return count;
    }
    public void setCount(int count) {
        this.count = count;
    }

    public void increment(){
        count++;
    }
}

<subDataset name="countDatasource" uuid="f6b4337c-45f4-4fc6-909a-ffbbef3a1b2f">
    <field name="description" class="java.lang.String"/>
    <field name="count" class="java.lang.Integer"/>
</subDataset>

告诉jrxml使用scriplet（您需要指明完整的类名，包括包名）

在

jasperReport

标记集

scriptletClass=“CountScriptlet”

定义子数据集

public class CountScriptlet extends JRDefaultScriptlet {

    private static final String COUNT_FIELD = "fieldNameYouLikeToCount";

    //Map to hold our count and dataset
    private Map<String,CountResult> ds = new HashMap<String, CountResult>(); 

    @Override
    public void afterDetailEval() throws JRScriptletException
    {
        String key = (String)this.getFieldValue(COUNT_FIELD);
        CountResult cr = ds.get(key); //Check if we have it
        if (cr==null){
            cr = new CountResult(key); //No, then create it count = 0
            ds.put(key, cr);
        }
        cr.increment(); //Increment it (new 0-->1, old i-->i+1

    }   
    public JRBeanCollectionDataSource getDataSource(){
        return new JRBeanCollectionDataSource(ds.values()); //Return our class as datasource, if you need to sort'em use Collections
    }
}

public class CountResult {

    private String description;
    private int count;

    public CountResult(String description) {
        this.description = description;
    }
    public String getDescription() {
        return description;
    }
    public void setDescription(String description) {
        this.description = description;
    }
    public int getCount() {
        return count;
    }
    public void setCount(int count) {
        this.count = count;
    }

    public void increment(){
        count++;
    }
}

<subDataset name="countDatasource" uuid="f6b4337c-45f4-4fc6-909a-ffbbef3a1b2f">
    <field name="description" class="java.lang.String"/>
    <field name="count" class="java.lang.Integer"/>
</subDataset>

在您喜欢的地方使用数据源（图表、表格ecc.）

---

唯一的限制是报告需要填写详细栏位（完成计数），因此您可以在

摘要

栏位或

reportElement

上使用它，使用

evaluationTime=“report”

您能提供更多详细信息吗？我不是Java开发人员，也是Jasper studio的新手。但我想学习如何去做。我来自传统的BI世界（SSRS，OBI），在那里这种操作非常简单直观。我知道Jasper可能更适合Java开发人员，但我想学习。谢谢。@thotwielder，好了，但你需要一些java来掌握窍门…：），你能提供更多细节吗？我不是Java开发人员，也是Jasper studio的新手。但我想学习如何去做。我来自传统的BI世界（SSRS，OBI），在那里这种操作非常简单直观。我知道Jasper可能更适合Java开发人员，但我想学习。谢谢。@thotwielder，好了，但你需要一些java来掌握窍门…：），玩得高兴